312 [September 



head densely punctured ; clypeus very transverse, fringed with pale 

 pubescence, and tinged with dark rufous ; mandibles very prominent, 

 long and rather slender, deeply bifid at tips, which are black, the rest 

 rufous and pubescent ; palpi pale rufous ; antennae short and stout, in- 

 volute, rufous at base, yellowish in the middle, and fuscous at tip, the 

 apical third beneath tinged with rufous. Thorax densely and finely 

 punctured ; mesothorax and scutellum flattened, the latter with two 

 deep, slightly transverse excavations in front; elevated lines of the me- 

 tathorax sharply defined, the central area rather large, transverse and 

 irregular, on each side of it are two spaces, the basal one large, some- 

 what rounded, smooth and shining, the posterior one smaller, oblique, 

 irregular and striated, posterior declivity abrupt, the lateral tubercles 

 scarcely visible ; tegulae rufous. Wings subhyaline, slightly and uni- 

 formly tinged with fuscous ; nervures fuscous, stigma pale fulvous ; 

 areolet 5-angular. Legs, with their coxae, rufous, pubescent. Abdo- 

 men subovate, polished, dark rufous ; basal segment gradually dilated 

 towards the tip which is broad and depressed, without lateral tubercles; 

 ovipositor short, rufous. Length 3| lines; expanse of wings 5f linos. 



Hab. — Illinois. Dr. Samuel Lewis. 



Easily distinguished from all the other species known to me by the 

 very prominent mandibles. 



Genus MESOSTENUS, Grav. 



1. Mesostenus albopictus, n. sp. 



Black, variegated with white markings ; antennse long, with a broad white 

 annulus ; legs yellow, posterior pair very long, mostly black ; wings hyaline ; 

 abdomen banded with white ; metathorax with two acute spines or tubercles. 



Male. — Black, shining, slightly pubescent; face beneath the anten- 

 nae, orbits, very broad behind, clypeus, labrum, base of mandibles, and 

 the palpi, white; antennae longer than the body, porrect, the 12th to 

 19th joints white. Thorax black, shining, densely punctured, the dor- 

 sal lines deeply impressed ; a line on the collar above and sides, a line 

 or spot in front of the anterior coxae, a round spot on the disk of meso- 

 thorax, tegulae, a broad sutural line before and a spot beneath the fore- 

 wings, a large, elongate, irregular mark on each side of the pleura, as 

 well as a slightly oblique line just bene:ith it in front of the middle 

 coxae, and a large transverse mark immediately behind the posterior 

 wings, all white ; scutellum subconvex, shining, punctured, its apex 



